To this division belong the Myophoria beds (M. Raibliana) with galena in places; the Estheria beds (E. laxilesta); the Schelfsandstein, used as a building-stone; the Lehrherg and Berg-gyps beds; Semionotus beds (S. Bergen) with building-stone of Coburg; and the Burgand Stubensandstein.
The tunnel runs in layers of Gipskeuper rock, containing anhydrite, which swell strongly when in contact with water.
Wide marshes, which rested on the impermeable layers of brick clay that lie on the Keupere, were not conducive to productive agriculture.
Geographically and geologically the land around Feuchtwangen comprises the eastern part of the Swabian-Franconian Escarpment Land (Schichtstufenland), also sometimes called the gypsum-keuper landscape.
As the name betrays, the term embraces both the keuper landscapes (including the well-known parts of the Keuper Upland Haßberge, Steigerwald and Frankenhöhe) and lias landscapes (Schwarzer Jura) in Franconia.